Oil and gasoline costs may be hovering near all-time highs, but natural gas prices are at less than half the record set late last year.

That means that people who heat their homes with natural gas, or about three out of five U.S. households, could see their bills decline this winter for the first time in five years.

Low prices could have a downside, says Porter Bennett of Bentek Energy. If prices stay low, energy companies will have less incentive to drill for natural gas. That will lead to lower supplies and, in the long run, higher prices, he says.

"The danger is that (the price) goes down too far and for too long. Then you've set up the next cycle," he says.